[rabbitmq-discuss] RabbitMQ Clustering

Sun Nov 27 02:32:09 GMT 2011

Good evening.
Following is our clustering scenario:
- Using RabbitMQ 2.6.1 with spring amqp 1.0 using RabbitMQ mirrored
queues
- We have two nodes on which queue consumers are running: q_c_node1
and q_c_node2.
- We have two rabbitmq nodes rmq_node1 and rmq_node2.
- Using HA Proxy to load balance.
- When q_c_node1 is started assume that there are two queue consumers
q_c1 using queue q1 and q_c2 using queue q2 are started. Assume that
HA Proxy routed the q1 creation to rmq_node1 and q2 creation to
rmq_node2.
- When q_c_node2 is started, q_c1 and q_c2 will be pointing to q1 on
rmq_node1 and q2 on rmq_node2 as q1 and q2 are already created (please
correct me if I am wrong).
- Assume that rmq_node1 is down. Since mirrored queues are used, we
have rmq_node2 as back up. The q_c1 consumer on q_c_node1 and
q_c_node2 will be pointed to rmq_node2 using HA Proxy and spring-
amqp's reconnecting mechanism. At this point two queue consumers
runnning on q_c_node1 and q_c_node2 are using rmq_node2 (as rmq_node1
is down). If a brand new rabbitmq node rmq_new_node joins the cluster
(using ha-x-policy-all, therefore this node also is mirrored) will it
scale as expected?. My concern is, q_c_node1 and q_c_node2 are
pointing to rmq_node2. Whenever requests go to rmq_new_node I am
assuming that they will be simply passed on to rmq_node1. How will the
CPU Utilization and I/O activity will be affected on rmq_node2 and
rmq_new_node?.

Thanks
Venkat